Anti-smog carburetor for internal combustion engines



July 18, 1967 1 FLEMiNG 3,331,360

ANTI-SMOG CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed July 22, 1966 4 Sheets-Sheet l \NCR EASED REAs 6% LOAD LOAD LEVEL DRIVE LEVEL DRWE UP GRADE DOWN GRADE EVE Dmve (3QMPH) 5 MPH) (30 MPH) (35 MPH) (30 MPH) 26 INTAKE A m MAN.PRESS. NORMAL DECREASES NORMAL NCREASES NORM L EXHAUST 317\POSITIVEPRESS NORMAL lNcRzAsEs NO MAL DECREASES NORMAL VENTURI PRESS. DROP REASES NORMAL \NCREAS I NORMAL RlCHER WX NORMAL LEANER M NORMAL FUEL/AIR EAF "MT RAT) (0R 'g X NORMAL SAME RATIO) ATiO) FIG. I

INVENTOR. ROBERT L. FLEMING BY 2 4 s /WMM ATTORNEYS July 18, 1%? R. FLEMING ANTI-SMOG CARBURETOR FOR INTERNAL COMBUSTION ENGINE:

Filed July 22, 1966 4 Sheets-Sheet ATTORNEYS July 18, 1967 R FLEM|NG I 3,331,360

ANTI-SMOG CARBURETOR FOR INTERNAL COMBUSTION ENGINE-S Filed July 22, 1966 4 Sheets-Sheet 3 9A FiG.

GROUND ELECTRO CHEMICALLY INVENTOR. ROBERT L. FLEMING FE 6. i0 a; su g MM 7 RN S July 18, 1967 R. FLEMING 3,331,360

ANTI-SMOG CARBUBETOR FOR INTERNAL COMBUSTION ENGINES Filed July 22, 1966 4 Sheets-Sheet 4 95 FIG. as

INVENTOR- ROBERT L. FLEMING ATTQRNEXSm United States Patent 3,331,360 ANTI-SMOG CARBURETOR FOR INTERNAL COMBUSTION ENGINES Robert L. Fleming, 260 E. 262nd St., Euclid, Ohio 44117 Filed July 22, 1966, Ser. No. 567,234 25 Claims. (Cl. 123-119) ABSTRACT OF THE DISCLOSURE A carburetor for internal combustion engines having a fuel dispensing stage for the liquid fuel which comprises a cup-shaped device having a foraminous wall through which liquid fuel from a fuel metering means is dispensed into the air stream of the carburetor. The liquid fuel is vaporized and atomized by passage through the minute openings in the fuel dispensing stage as a result of the size of the openings and the intake air passing adjacent to the fuel stage so that a substantially homogeneous mixture of intake air and charged fuel may be presented to the internal combustion engine from about the periphery of the fuel dispensing stage. The fuel flow rate of the disclosed carburetor is controlled by a positive-pressure system operative in conjunction with a metering valve to reduce the fuel flow under decelerating engine operation to provide increased fuel economy and anti-smog? capabilities.

Cross references to related applications This is a continuation-in-part of my prior copending application, Ser. No. 386,240, filed July 30, 1964, now Patent No. 3,269,377, issued Aug. 30, 1966.

Background and summary of the invention This invention relates to carburetors for internal combustion engines and more particularly to a carburetor in which the liquid fuel is precisely metered through a continuously adjustable metering valve, and nearly instantaneously vaporized or atomized in a fuel stage without the need for heating the fuel above its boiling point, thereafter mixing the fuel in its vaporized or atomized state with the intake air when both constituents are in a readily miscible form.

The functions of this new type of carburetor are performed basically in two stages operating simultaneously. The first stage performs the operation of precisely metering the liquid fuel past a cam-operated metering valve having a variable positive pressure drop across the valve. Subsequently, the metered liquid fuel is dispensed into a vaporization or atomization area through a fuel dispensing stage, where the second stage of operation occurs in which the liquid fuel is nearly instantaneously vaporized or atomized by action of the liquid fuel passing through a plurality of holes in a fuel dispenser. The intake air passing adjacent to the fuel dispenser creates a Bernoulli effect, thus cooperating with the device to effect an atomization or vaporization of the liquid fuel by the action of the air to shear the particles of liquid fuel as they pass through the holes in the fuel dispenser. Thus, the fuel may be atomized or vaporized or both for intermixture with the intake air and used in the internal combustion engine without the need for heating it beyond its boiling point to create the gaseous state of the fuel.

The two stages of operation occur on a continuous basis wherein the gaseous fuel is admitted to the air stream just ahead of the throttle plate through equally spaced radial ports in the fuel dispenser by a 360 presentation of fuel to the intake air thereby to provide a uniform intermixing of fuel, in its atomized or vaporized state, and intake air, of course, in the gaseous state, to a conventional internal combustion engine, using gasoline or other similar type fuel. Since the fuel is either Patented July 18, 1967 atomized or vaporized on both in cooperation with the action of the air passing adjacent to the fuel dispenser, the volumes of atomized or vaporized fuel and air are effectively in the gaseous state and thereby readily diffuse into each other to conveniently effect an air-fuel mixture, and become a homogeneous mixture, thus creating a uniformity in the fuel-air-mixture of the two gases which is unequalled by any other carburetor design and which thus eliminates the basic deficiency of present-day carburetors, which is a major contributor to the creation of smog and general air contamination. In general, the homogeneous mixing of fuel and air in this new carburetor promotes nearly percent combustion efficiency, thereby eliminating or minimizing incomplete combustion and the resulting smog-creating byproducts.

The liquid fuel metering valve is operated directly by the throttle plate with a positive pressure-drop across the valve to vary the rate of fuel flow according to the needs of the engine. The use of a metering cam makes it possible to control precisely the variation of the volume or fuel rate of flow according to the individual characteristics of an engine model type and to compensate for each different engine design and functional variation or both under all operating conditions and speed. This is not unlike the metering of fuel in conventional carburetors through fuel jets, and the like, but, in the carburetor of the present invention, the fuel is metered to a higher degree of accuracy in the control of fuel flow rate.

The throttle plate is the primary control for varying the fuel rate of flow for normal engine operation, and a secondary control is made possible through a variable positioning pin, thus controlling the relative position of the fuel metering cam on the throttle plate to take care of abnormal engine operations, such as choking under cold-starting operations and also for acceleration and deceleration operating conditions. Thus, these two mediums of control over the fuel rate of flow allow this carburetion system to match the needs of the engine automatically to the full range of engine operating conditions from operating through full power to engine braking.

For instance, if the engine accelerates, the throttle plate increases its opening, as usual, to admit more intake fuel-air mixture to the engine, which causes the fall of the primary control cam to increase the fuel flow rate in proportion to the increased flow rate of the intake air, as for normal engine operation. In addition to this primary control, the quick action of fast acceleration conditions causes the secondary control temporarily further to increase the fuel flow rate by physically lowering the cam, until the engine acceleration has matched the load and is up to the speed representative of the new position of the throttle plate or degree of opening in the carburetor throat. The secondary control then automatically returns the cam to its normal operating relative throttle plate position by physically raising it toward its original position, until a further need of the engine arises, causing the secondary control again to operate in a manner similar to that described above.

With this preliminary understanding of the mode of operation of this anti-smog carburetor in charging intake air with fuel and the manner in which it operates under various normal and abnormal engine operating conditions, the details of operation,- described in the following presentation, will provide a clear understanding of the carburetor, its parts, and their corresponding functional interrelationship, together with the similarities and differences between the carburetor of the instant invention and present-day carburetor designs. This description will provide a clear understanding of the need for specific elements of hardware in this new design to provide the necessary control over the aforementioned functions and conditions of operation and the interrelationship of these various elements of hardware.

This new and different basic improvement pertains to a carburetor in which the liquid fuel, such as gasoline, but not restricted thereto, is precisely metered through a metering valve, which may be, but is not necessarily, of the needle type, which is continuously adjustable and simultaneously operated in conjunction with or by a throttle plate or other type of air valve, thereby to maintain a nearconstant fuel-to-air ratio by weight under normal engine operations. The metering valve is controlled by a cam which varies with the throttle plate position and may also be controlled by the positive pressure-drop across the metering valve. The fuel-to-air ratio by weight can be fuel-enriched under automatic choking and/or accelerating operations, or fuel-leaned under decelerating engine operation.

Positive pressure is obtained from a static pressure tube, in a downstream direction inside the exhaust manifold of an internal combustion engine. The static pressure tube senses changes in the exhaust gas pressure at that point, which reflect changes in gas pressure within the cylinder and/ or the quality and quantity of combustion gases under all conditions of engine operation. For example, gas pressure increases under accelerating or increasing torque engine operations and decreases under decelerating or decreasing torque engine operations.

This carburetor differs further from conventional vacuum pressure operated carburetors in that the fuel is intermixed with the air stream by a fuel dispensing stage, which comprises a fuel dispenser including a plurality of minute holes (approximately 0.0002 to 0.0010 inch diameter) which are equally spaced on its flanged periphery. The fuel stage dispenses the fuel on a uniform basis to attain a near-homogeneous mixing of fuel in atomized or vapor form, closely resembling the near-homogeneous mixing which is obained by an LPG (liquified petroleum or bottled gas) carburetor. This near-homogeneous mixture of atomized or vaporized fuel particles in their vapor or near-vapor form with the intake air promotes near- 100 percent combustion efliciency, thus promoting cleanburning engine operations in a manner like an LPG carburetor. This results in a very low content of hydrocarbon and similar smog-producing air contaminants in the exhaust gases from the engine compared to the conventional vacuum pressure operated gasoline-carburetorequipped internal combustion engine.

Further advantages of this new carburetor improvement are faster engine warm-up due to improved combustion efiiciency, automatic compensation of the fuel-to-air ratio in terms of volumetric weight during changes in the atmospheric pressure and during accelerating and decelerating engine conditions, as well as during various possible attitudes of either the engine or vehicle or both with respect to the horizontal plane, for example, in turning corners or other such forces that normally effect the metering of liquid fuel in a conventional carburetor. These problems are remedied in the novel carburetor of the instant invention by virtue of its positive pressure and confinement features of its constantly replenished fuel supply reservoir.

A further advantage of this carburetor improvement is the constant introduction of hot exhaust gas from the exhaust static pressure tube, which conduct and dissipate their heat directly to the metering valve and fuel stage, thus preventing icing conditions in the carburetor when either climatic or atmospheric conditions or both are such that icing conditions would be created in a conventional carburetor. The exhaust static pressure tube may also introduce water vapor from the hot exhaust gases which may be of significant quantity to act as a catalyst to increase power and improve engine operation as normally occurs under high humidity atmospheric conditions.

Another important advantage of this new carburetor improvement is in the use of a positive reference pressure drop across the metering valve instead of the conventional vacuum, or atmospheric, pressure, and it is this particular feature of this improved carburetor design and operation, which provides its so-called anti-smog capabilities, which a vacuum pressure operated carburetor, as heretofore known, cannot possibly attain, The positive reference pressure can be obtained from the aforementioned exhaust static pressure tube installed in the exhaust manifold of the internal combustion engine, or it may be provided by a more elaborate outside pressure source and control equipment. This very unique capability will be discussed in greater detail in connection with the discussion of the figures of this specification.

Thus, all of the advantages set forth above of this new and novel basic carburetor improvement accumulatively provide an over-all increase in the mileage rate per gallon of fuel for a given driver and car combination over the same combination operating over the same route and under the same driving conditions in comparison with a conventional type vacuum pressure operated carburetor on the engine of the vehicle. Because driving habits have much to do with the actual mileage economy obtained on the same car driven by different drivers, an identical mileage rate per gallon is unlikely, although the percentage of improvement would be much closer, if not identical, among most drivers.

With the problems of the prior art carburetors in mind, it is a general object of this invention to provide a new and improved carburetor.

It is a further object of this invention to provide a new type of carburetor which precisely meters the liquid fuel, vaporizes the fuel and mixes the fuel vapor with the intake air.

It is a further object of this invention to provide a carburetor in which metered liquid fuel is nearly instantaneously vaporized by passing the fuel through a plurality of openings in a fuel dispensing stage thereby atomizing or vaporizing the fuel by the shearing action of the air passing adjacent to the fuel dispensing stage.

It is an additional object of this invention to atomize the liquid fuel in a carburetor for homogenous intermixture with the intake air without the need for heating the fuel beyond its boiling point in a vaporization chamher.

It is another object of this invention to provide a novel and improved carburetor in which gaseous fuel is intermixed with an air stream to provide a uniform intermixing of fuel in its atomized state.

It is still a further object of this invention to provide a carburetor whose operation provides a homogeneous mixture of fuel and air which is unequalled by present carburet-or designs.

It is still a further object of this invention to provide a homogeneous mixture of fuel and air to promote near perfect combustion efficiency, thereby to eliminate and minimize incomplete combustion and the resulting smogcreating by-products.

It is another object of this invention to provide a carburetor which has a fuel dispensing stage comprising a plurality of holes through which gas passes in its liquified form to be thereafter atomized or vaporized by the action of the intake air passing adjacent to the fuel dispenser.

These and other advantages and objects of this new and different basic improvement in a gasoline type carburetor will become apparent from the description of the carburotor with reference to the accompany drawings.

Brief description of the drawings FIG. 1 is a graphical comparison of the fuel-to-air ratio of the carburetor according to the invention and the fuel-to-air ratio of a conventional vacuum pressure operated carburetor, under various conditions of operation.

FIG. 2 is a side elevation sectional view of the carburetor on line 22 of FIG. 4.

FIG. 3 is one end view of the carburetor and a partial section along line 3-3 of FIG. 2.

FIG. 4 is a sectional view through the throat area of the carburetor along line 4-4 of FIG. 2.

FIG. 5 is a view in greater detail of the fuel metering stage of the carburetor of FIG. 2.

FIG. 6 is a view in greater detail of the fuel dispensing stage in the carburetor of FIG. 2.

FIG. 7 is a partial sectional view through the idle fuel flow shut-off valve and idle mixture needle valve on line 7-7 of FIG. 4.

FIG. 8 is an enlarged view of the pyramid-shaped indents which are cold-formed on the inside flange surface of the fuel dispensing stage.

FIG. 9 is a sectional view taken along an axis of the fuel dispensing stage of the carburetor according to the instant invention.

FIG. 9a is a partial sectional view taken on line 9a-9a of the fuel dispensing stage of FIG. 9.

FIG. 10 is a partial sectional view on line 1010 of FIG. 4.

FIG. 11 is a partial sectional view on line 1111 of FIG. 2.

FIG. 12 is a partial sectional view on line 1212 of FIG. 2.

FIG. 13 is a sectional view of the exhaust static pressure tube and carbon trap-flame arrestor support equipment.

FIG. 14 is a sectional view of the variable position spark advance operator support equipment to the carburetor.

FIG. 15 is a sectional view of the vacuum pressure control slot and communicating holes on line 1515 of FIG. 4.

FIG. 16 is a view of the vacuum pressure control slot taken along line 1616 of FIG. '15.

Throughout the specification, and in the drawings, similar numbers refer to similar parts throughout the several views of the carburetor and support equipment.

Description of the preferred embodiments FIG. 1 is a logical analysis of the fuel-to-air ratio variation under the conditions of a fixed throttle plate in a partial open-throttle position providing a vehicle speed of 30 miles per hour in level drive. The purpose of FIG. 1 is to graphically compare the operation of vehicles equipped with the carburetor according to the invention, with the operation of vehicles equipped with a conventional vacuum pressure operated carburetor, as presently furnished on vehicles. Where different, the conventional carburetor operation is shown by the dashed lines.

FIG. 1 graphically illustrates various operating conditions including level drive, and increased and decreased load of a vehicle equipped with the conventional carburetor and the relationship of the car speed 1, intake manifold pressure 2, venturi pressure drop 3, and fuel-'to-air ratio 4, for various riding conditions, such as level drive at 30 miles per hour, increased load in an uphill grade at miles per hour, level drive following up grade at miles per hour, decreased load in a downhill grade of up to miles per hour, and return to level drive of 30 miles per hour. It can be seen that, for vehicle velocity which may be termed normal in a level drive, 30 miles per hour, situation, solid lines 1 through 4 are termed normal operating conditions.

When the vehicle traverses an uphill grade, for example, one on which the vehicle must accelerate, it can be understood that as the vehicle slows, the engine speed 1 thus decreases, causing the volume of air drawn to the carburetor to decrease and thereby decreases the intake manifold vacuum pressure 2. This also produces a lower intake air velocity in the carburetor which decreases the venturi pressure drop 3. Thus, less fuel passes the jets of the conventional carburetor, resulting in a leaner mixture 4. Ac-

cordingly, to obtain satisfactory operations in an acceleration condition, a conventional vacuum pressure operated carburetor needs a richer fuel-air ratio under level drive conditions to anticipate acceleration conditions.

In a level drive condition following an up grade condition, the engines speed 1 returns to normal, producing a normal intake manifold vacuum pressure 2 and a normal venturi pressure drop 3. Thus, a normal fuel-to-air mixture ratio 4 results for this particular vehicle speed. Accordingly, the fuel-to-air ratio 4 must tend toward the rich-infuel domain on normal drive since the venturi pressure drop 3 decreases on slow acceleration and thereby causes engine lag, to a progressive stall, if the carburetor were normally set toward the lean conditions.

Continuing with the vehicle equipped with the conventional vacuum pressure carburetor of FIG. 1, suppose that the vehicle then comes to a decreased load condition, as would be the case in a downhill grade where the car would tend to speed up to, for example, 35 miles per hour. Under these conditions, the faster engine speed 1 increases the volume of air drawn to the carburetor, and thereby increases the intake manifold vacuum pressure 2. This action produces a higher air velocity in the carburetor and an increased venturi pressure drop 3, thereby forcing more fuel to pass the jets, thus producing a richer mixture, shown at 4.

Accordingly, vacuum pressure operated carburetors can never have anti-smog capabilities because the richness or the leaness of the mixture may vary according to the driving conditions. It can thus be seen, that a vehicle equipped with conventional vacuum pressure operated carburetor is likely to produce unburned hydrocarbon and other contaminant gases because of low combustion efiiciency for the reason that upon decreased load, the resulting richer fuel-air ratio causes excessive emission rate of smog-creating constituents.

FIG. 1 also compares the parameters heretofore dis cussed, namely car speed 5, intake manifold pressure 6, exhaust positive pressure 7, and fuel-to-air ratio 8, which correspond to similar parameters 1 through 4, for a vehicle equipped with the new carburetor.

With the carburetor according to the instant invention, under an increased load or uphill grade condition which would tend to slow the vehicle to, for example, 25 miles per hour, the correspondingly lower engine speed 5 reduces the volume of air drawn through the carburetor and decreases the intake manifold pressure 6, similar to the conventional carburetor. However, with the positive pressure carburetor of the instant invention, the exhaust positive pressure 7 increases, thus causing more fuel to pass the metering valve to provide a richer mixture thereby permitting the carburetor of the instant invention to operate under normal conditions with a leaner normal fuel-to-air ratio. Under level drive conditions, the engine speed 5 is normal, the intake manifold 6 and exhaust positive pressure 7 are normal and provide a normal fuel-toair ratio 8 at this speed. According to the invention, this may tend toward the lean in fuel domain, because positive pressure on slow acceleration would normally enrich the mixture. This effect is desirable to match the increased wheel torque.

Under a deceleration condition for a vehicle equipped with a positive pressure carburetor, for example, where the vehicle approaches a downhill grade and would thus tend to speed up to, for example, 35 miles per hour, the correspondingly faster engine speed 5 increases the volume of air drawn to the carburetor and increases the intake manifold vacuum pressure 6, similar to a conventional carburetor. However, this deceleration condition also produces a decrease in the positive pressure 7 of the exhaust, thus causing less fuel to pass the metering valve, resulting in a leaner-in-fuel mixture 8. Thus, on deceleration, the leaner fuel-to-air ratio causes far less emission of smog-creating constitutents than in a conventional carburetor. This also results in a very high combustion efficiency, approaching 100 percent, and additionally pro vides anti-smog capabilities.

In FIGS. 2 through 4, the carburetor includes a substantially oval-shaping casing, generally indicated at 10. The casing comprises a lower portion 11, which may be diamond-shaped and formed to create a base with periph eral flange 12. Peripheral flange 12 contains a plurality of holes 13 for reception of fastening means, for example, screws or bolts, by which the casing may be mounted over an opening in the intake manifold of an internal combustion engine (not shown) such as the engine of an automobile, truck, bus or other vehicular or stationary power plant.

The lower portion 11 serves as a base and mounting for a throttle plate type air valve 14 positioned in the throat area through the lower portion 11 from the bottom to the top. The throttle plate type air valve 14 is secured to a tubular throttle plate axle 15, with journals 15a at both sides of the throat opening, so that the throttle plate may pivot about an axis through axle 15 and thereby increase or decrease the throat area and thus control the intake air throughput.

A metering cam base 16 is suitably fastened by screws 17, or other convenient fastening means to the throttle plate 14, and is located on the upper side of throttle plate 14 within the confinement of a flat on the tubular throttle plate axle 15, as can best be seen in FIGS. 4 and 10.

A metering cam 18 is mounted in cam base 16 in a pivotal relationship by pin 19, with its free end engaging positioning pin 20. The positioning pin 20 is piloted within cam base 16 and extends into a suitable clearance hole in throttle plate axle 15 so that the spherical radius end of positioning pin 20 opposite from the end engaging metering cam 18 is in contact with the conical surface of the inner end of the adjustment rod 21. Adjustment rod 21 is loosely and slidably fitted inside tubular axle 15 to permit convenient adjustment which will be hereinafter further discussed.

As can be seen in FIGS. 2 and 11, the adjustment rod 21 may be displaced axially by means of the fixed pin 22 in the adjustment rod 21 which is positioned in a straight elongated slot 15b in the tubular axle 15 and its cammed relationship to helical slots 23a in the tubular hub 23 of inertial flywheel 24. The flywheel 24 is piloted on tubular axle 15 by bearing 25, so that the inertial flywheel 24 may have angular displacement or rotation with respect to the tubular axle 15, and thereby act as a cam-out screw when the throttle lever 26, which is held in a tight frictional relationship with axle 15 by clamp screw 27, is pivoted by linkage to an accelerator pedal (not shown).

Since the motion of the accelerator pedal and the accompanying linkage is more rapid than inertial flywheel 24, assisted by an air-dashpot with an adjustable lead (not shown), and will thus accelerate, this action causes the adjustment rod 21 to have a temporary axial displacement. The axial displacement will continue until return spring 28 creates a time delay of suitable duration to permit the positioning pin 20, shown in FIGS. 4 and 10 to readjust the metering cam 18 to a more open valve position and thereafter return to its normal reference position by the action of return spring 28. The spring load and the retarded motion of the air-dashpot create a time delay suitable to allow the positioning pin 20 to perform this task.

The phantom outline 21a, in FIGS. 2 and 11, shows the adjustment rod 21 in its position of maximum displacement. The return spring 28 may be adjustable in its spring rate, or tension, and thus capable of varying the acceleration rate of the engine to increase speed, by means of its anchorage clamp 29, with a plurality of set screws 20, by which the number of active coils of the return spring 28 can be changed from a maximum to a minimum number of coils in torsional stress by tightening or loosening one or more of the set screws 30.

The anchorage clamp 29 is fixed t-o inertial flywheel 24 by means of screw 31 and rotates with the flywheel 24 so that the return spring 28, which acts in torsion like a clock spring, applies a spring load with its engagement leg 32, as can be seen in FIG. 3, in contact with the idle mixture adjustment rod bracket 33. This causes the inertial flywheel 24 to follow the rotation of the adjustment rod bracket 33 under a delayed time period, which is necessary for accelerating the engine with the fuel enrichment that this inertial flywheel assembly provides according to the readjustment cycle of the metering cam, as previously described.

The idle mixture adjustment rod bracket 33 has an adjustment screw 34, which bears against pin 24a and permits variation in the fuel-to-air ratio at the idle speed range, which thereafter automatically maintains this ratio for all other normal engine speeds.

Directly above metering valve cam 18, as can be seen in FIGS. 2 and 10, the fuel metering valve 35, with its spring 36 acting to spring load the valve 35 against the cam surface of the metering cam 18, thus controlling the opening in the metering orifice 37 with respect to to conical surface 38 at the upper end of metering valve 35. By precisely varying this opening in meter orifice 37 the flow rate of fuel may thus be controlled in conjunction with the positive pressure drop across the metering valve. The metering orifice 37 is in a fixed position in the carburetor casing 10, in the central cone-shaped portion 10a, which is suspended near or at the middle of the carburetor through-throat area by strut members 39 and 40.

A hole is drilled in strut 39 at an angle which permits it to communicate with a cross-drilled hole from a fuel strainer 41, which is similar in construction to the fuel stage. The fuel passes from the outside diameter to the inside diameter of the fuel strainer 41, thus preventing foreign particles from passing through to the fuel stage. The fuel strainer 41 may be held in a counterbore area at the bottom of the constantly replenished fuel chamber by a wire snap ring 42 as shown in FIG. 12.

The blind end of the long drilled hole in strut 39 communicates with the drilled holes from the top end of metering orifice 37 in the cone-shaped portion 10a. A reamed opening in strut 40, parallel to the throttle valve axle 15, retains tubing member 43 which is piloted into an annular counterbore 44 which generally surrounds the metering orifice 37 with vaporization nozzle 45. This structure forms an outlet for the hot exhaust gases, directing them down upon the fuel dispensing stage 46, which is held in a fixed relation on the stem of metering valve 35 and whose motion is coincident with the metering valve.

The metering valve stem is supported in a sliding set relationship in valve guide 47, which has radial legs or struts 47a which connect the circular ring portion 47b and rest in a suitable counterbore in the bottom of the through-throat area of casing 10,

The accelerator pump 48 operates in a bore in casing '10 which communicates with the long drilled hole in strut 39 and is operated by rod linkage 49. A bent leg of rod linkage 49 becomes the pivot pin 19 for metering cam 18 at one end, is attached to the idling positive pressure vent valve operator 50 at the other end of the linkage. Operator 50 unseats the positive pressure vent valve 500, which is spring loaded to seat upon the open end of tubular member 51 which is connected into the upper carburetor or cover 52.

An intake air velocity orifice plate 53 anchors the spring loaded vent valve 50a and pilots the upper end of the stem of accelerator pump 48. A ball check valve 54 seats on tubular member 54a. Tubular member 54a is fitted into the lower section of the long drilled hole in strut 39 to provide a leak-proof fit, and this intercepts the fuel passage to the metering orifice 37 so that under accelerating conditions, the accelerator pump 48 injects a suitable additional volume of fuel to the fuel metering valve 35 under positive displacement. Therefore, the new throttle position for a higher engine speed establishes a new fuel rate of flow which unseats the check valve 54 from seat 54a and normal precision fuel metering is resumed.

The aforementioned vent valve tubular member 51 connects at the upper carburetor casing or cover 52 and communicates with seal chamber 55 of the carburetor which contains the combination float operator 56 and pressure differential diaphragm 65. The float operator 56 has a stem portion 57 with a pin therethrough which captures the elongated slot of lever 59. This, in turn, captures and pivots on wire form 60 which is confined in the vertical groove b in the side of the fuel supply chamber on either side of the fuel inlet fitting 61 which is screwed into a boss on the side of casing 10.

The inlet fitting 61 has a needle valve seat which engages the needle valve 62 when the valve is displaced by leg 63 on lever 59. This is, in turn, controlled by the float operator 56 as the liquid level of the fuel rises and falls under the normal continuous flow of fuel to the engine while it is in operation. A gasket 64 seals the threaded connection of the inlet fitting 61 and the carburetor casing 10. The flexible pressure differential diaphragm portion 65 of the combination float operator 56 has an inverted conical shape 66 that is molded as a single conical shape with circular flange portion 67. The circular flange portion 67 may be squeezed to an air-tight seal between the recess in casing 10 and the bottom surface of upper portion 52 through gasket 68.

Exhaust static positive reference pressure is ported into the sealed air chamber 55 by communicating tubing (not shown) to chamber fitting port 55a and is thereby transmitted to the effective area of the inverted conical diaphragm so as to cause an identical pressure to the confined liquid fuel, which in turn causes a suitable fuel pressure drop across the metering orifice and common opening of the metering valve at all speeds of engine operation, except in the lower idling speed range. For the lower idling speed range, the conventional carburetor adjustable metering needle valve is at a position just below the throttle plate as used, suitably communicating with the fuel strainer counterbore. Art the open end of the long drilled hole in strut 39, a sealing plug 69 is permanently pressed into place in casing 10.

As shown in FIGS. 2 and 3, the tubing member 43 has a heat-sensing bi-metallic spring-type thermostat element 70 in fixed relation to its housing 71 to conduct heat from the inside diameter of the housing 71 through the bi-metal element. The housing is adjustable to pivotal and axial location on the tubing 43 by means of set screws 72 so that leg 73 of the bi-metal element can be adjusted to operate tang 74 of the vertically slidable ratchet pawl 75 which is guided and held by fixed bracket 76 with the assembly :anchored to carburetor casing 10 by screw 77.

This thermostat assembly is set for a predetermined period of elapsed time, satisfactory to the necessary choking, or fuel enrichment cycle, of the engine during warm- The inertial flywheel 24 has a suitable plurality of ratchet teeth notches 78 in one segment of its peripheral surface to engage corner 75a of ratchet pawl 75 so that a clockwise rotation of the inertial fly-wheel 24 would escape one or more of the notches 78 when the bi-metallic element 70 allows the ratchet pawl 75 to hang low enough to engage said notches. When a satisfactory temperature of element 70 is reached, the leg '73 lifts the ratchet pawl 75 up and out of the engagement path. Thus, when the accelerator pedal is depressed prior to the necessary warm-up period of engine operation, the inertial flywheel 24 will not rotate with the throttle plate axle assembly, thereby causing the maximum of fuel enrichment at all speeds during the brief warm-up period, after which it operates in its normal way as previously described. The idle engine speed adjustment screw 79 as shown in FIGS. 3 and 11, is held in projected portion 80 of casing 10, such that the screw bears against the outside diameter of 10 pin 81 which is in a fixed position in throttle lever 26 and parallel with tubular throttle axle 15. The hole 82 in throttle lever 26 provides a suitable pivot point for linkage to the accelerator pedal (not shown) as is in common use in present-day automobiles.

FIG. 6 shows a detailed view of the fuel stage which includes a skirt 45a and nozzle means 45. A cup-shaped fuel dispenser 46 is shown as comprising a plurality of openings thereon, preferably square openings. The cupshaped fuel dispenser is secured to the fuel metering valve 35 and is free to move therewith. It can be seen that when the fuel metering valve 35 moves downward in response to action of cam 18 according to the needs of the engine operation, the fuel dispensing stage plate 46 will also move in a downward position thereby exposing more of the openings in the plate to the path of the intake air. This operation is such that the fuel is retained under pressure behind the plate 46, in such a manner that due to the combined efforts of the pressure behind the plate and a draft of the intake air, the engine fuel is forced through the openings of the fuel dispenser and atomized thereby to eifecta homogeneous intermixture of air and gas. The action in performing this function may be considered to be a shearing action in which volumes of air effectively shear the particles of liquid fuel which appear at the surface of openings 46a so rapidly that the fuel effectively atomizes and is thus capable of combination with the air to produce the homogeneity desired. Since the movement of the fuel dispensing stage 46 is in conjunction with the metering valve 35, it can be seen that the analysis heretofore presented with respect to increasing or deceasing the richness or leaness of the fuel-air mixture is accordingly applicable here.

FIGS. 9 and 9a show the fuel dispensing stage of FIGS. 2 and 6 in greater detail. Fuel dispensing stage 46 is essentially a cup-shaped part which has been drawn and formed to a convenient cup outline and according to conventional practice. A machine piloting a back-up roller inside the cup forces pyramid shapes on the surface of the roller die to cold form indents as shown into the inside diameter of the cup-shaped fuel dispenser 46. The part may be made of a soft brass or steel or other suitable material. After the cold formed internal pyramidshaped cone indents are formed by the inner roller die on the inner surface of the cup-shaped fuel dispenser 46, the outer diameter may be ground to a smaller diameter thereby to result in a square opening 46b on the outside diameter of the cup-shaped part approximately of 0.0005 to 0.001 inch in dimension. The openings 4611 are of a substantially square configuration due to the truncation of the pyramid-shaped indents 46a by grinding the outer diameter of fuel dispenser 46.

These openings may be made relatively burr-free by the use of a deplating type electro-chemical grinding operation. After grinding, the fuel stage may be plated by an electrolyzing process to a thickness of .0002 to .0004 in. and .a hardness of RC 68. In this manner, the high degree of accuracy in the opening size may be maintained. It can be seen that after the pyramid-shape indents 46a on the inside diameter of the cup-shaped fuel dispensing stage 46 are ground, openings are created to the Outside of the fuel dispenser 46 as shown at 4611.

FIG. 8 shows an enlarged view with the pyramidshaped indents which are cold formed on the inside flange surface of the fuel stage. It has been found desirable to keep points of the pyramid-shape as sharp as possible in the forming stage so that when the outside diameter fuel stage is ground electro-chernically, a high degree of consistency in the dimension of the openings may thereby be provided, even when ground very slightly to expose only a minimum dimension of the openings.

FIG. 7 shows a view through the idle fuel flow shutoff valve and idle mixture needle valve along line 77 of FIG. 4. A partial sectional View of the shut-off valve of the idle fuel system comprises a cam lobe 112 attached to throttle plate 14 which operates against a radius nose 113 of the O-ring shut-off valve stem 114 in opposition to spring 115 which is mounted inside housing 116. The O-ring 117 provides a leak-proof shield with valve seat 118 thereby preventing idle flow fuel from feeding down from the fuel bowl in casing through the peripheral recess 119 of the circular ring portion 47b of valve guide 47. Circular ring portion 47b is confined with its mating counterbore in casing 10 through the shut-off valve by means of communicating holes to needle valve 120 and its mating conical valve seat opening 121 and lower housing 11. A compression spring 122 is provided under the head of the threaded needle valve 120 and assists the needle valve in maintaining its fixed setting.

When the vehicle is operated under idle speed conditions, as hown in the near-horizontal phantom outline of throttle plate 14, the cam lobe 112 depresses the shut-off valve stem 114, thus lifting the O-ring 117 from valve seat 118 and allowing a full flow of idling fuel to the idle mixture needle valve 120.

In the solid outline position of throttle plate 14, which is the position that would be assumed for an engine speed above idle, the cam lobe 112 loses contact with the radius nose 113 of the shut-off valve stem 114 allowing it to close fully under the spring load, thus cutting off fuel flow to the needle valve 120 under all speeds above the idling speed range. Under the idle speed only the carburetor operates as a conventional gasoline carburetor in that the fuel is presented to the intake air stream at its point of highest velocity just below the throttle plate. At all other engine speeds, this fuel path is completely shut off and the carburetor operates as an anti-smog carburetor, as hereinbefore described, with all fuel passing through the precision cam-operated central metering valve 35 to the fuel stage 46 where the fuel is uniformly distributed over a plurality of minute holes.

Thus, separate fuel paths having tapered openings 46a with sharp edge hole terminations 46b as shown in FIGS. 8 and 9 and as hereinbefore discussed, produce a fuel particle size in the near vapor range. These fuel particles are continuously presented to the air stream at its point of highest velocity at a full 360 circular or peripheral path.

This unique method of charging intake air with fuel vapor produces a refinement in the fuel-air mixture that is as near homogeneous as is practical to attain without elevating the fuel particles to a temperature above their boiling point as described in my application, Ser. No. 386,240, filed July 30, 1964, now Patent No. 3,269,377, issued Aug. 30, 1966.

As is shown in FIG. 13, a tubing member 43 from the carburetor (not shown in this view), has a male flare tube fitting 83 threadedly engaged with the top half of a carbon trap flame arrestor 84 which, together with the lower half 85, forms a closed chamber with a taper seal joint 86 held together by a bolt nut assembly 87 and 88 in conjunction with the welded washer/flanges 89 and 90. The top half of carbon trap flame arrestor 84 includes an offset internal communicating tube 91 having an outlet end which passes a similar offset tube 92 which projects into the upper half in such a manner that any carbon or other foreign deposits which may be carried in the exhaust gases can be filtered out before reaching the carburetor. In the lower half of the carbon trap-flame arrestor 35, a flow rate adjustment screw 93 with a jam nut 94 provides control over the amount of hot exhaust gases that can pass therethrough, so that an excess of heat can be prevented from causing partial vaporization of the liquid fuel as it is flowing through the metering valve.

In addition, the exhaust static positive reference pressure tap tube 85a is contained within the lower half 85 of the carbon trap flame arrestor and communicates with a similar static pressure tap tube in chamber fitting port 55a by means of suitable tubing (not shown).

The exhaust static positive reference pressure tube 95 has an angular cut-off surface 96 which result in an elliptical shaped opening to slow down the velocity of the exhaust gases entering the static pressure tube. This further aids the exclusion of carbon and other solids from the tube, one end of which is welded to a diamond-shaped or any other exhaust manifold connection hape of flange 97 having a slightly greater thickness than the outside diameter of the static tube 95.

An additional tubing member 98 is abutted and welded to this welded flange, so that the communication of hot exhaust gases continues from the static pressure tube through tubing member 98. Tubing member 98 may have its flared end with male flare tube fitting 99 screwed into the lower half 85 of the carbon trap flame arrestor assembly.

In FIG. 14, a variable position spark-advanced diaphragm type operator is shown in which the back housing 100 has a female flare tube fitting 101 and an inverted conical shape flexible diaphragm 102 which has its peripheral flange 103 captured in an air-tight connection with front housing 104 by a crimped-type of peripheral closing operation on the flange of back housing 100.

A stem portion 105 of the diaphragm 102 extends through a loop guiding clearance hole in the front housing 104 such that air is vented from the chamber of the front housing side of diaphragm 102 through to the distributor housing (not shown). Diaphragm 102, back up inner disc 106, and outer disc 107 are held in an air-tight riveted assembly with the flexible diaphragm 102. The assembly is spring loaded by a spiral type compression spring 108 with a desired variable spring rate, so that a suitable variable vacuum pressure created beyond the throttle plate in the aforementioned carburetor and conducted to the female tube fitting 101 by a suitable tubing (not shown) to communicate with similar female flared tube fitting 109, as shown in FIG. 2, will satisfactorily reposition the spark-advance mechanism in the distributor so that each throttle position has a more ideal sparkadvance position.

In FIG. 15, a sectional view of the vacuum pressure control slots is shown as machined into the throat area similar to FIG. 4 so that angular, or rotational, movement of the throttle plate 14 progressively uncovers a greater flow area of this vacuum pressure slot 110 from a minimum flow area at idle engine speed to a maximum flow area at wide open throttle engine speed. A drilled hole 111 at a suitable angle communicates with the female flare tube fitting 109 to the vacuum pressure control slots 110 so that sufficient flow area in thi wide-open throttle position reduces the vacuum pressure to the spark-advance diaphragm operator to a minimum, leaving the distributor in its fully-advanced spark-position. At the other extreme position, the throttle is nearly closed in its idle engine speed position which will produce a maximum vacuum presure to said spark advanced diaphragm operator, thus retarding or moving the distributor to its fullyretarded spark position. In the idle speed position, the throttle plate completely closes off the flow control slots 110 from the near atmospheric pressure above the throttle plate, thus maintaining a maximum of vacuum pressure and a the throttle plate is opened, exposes progressively more of the area of the flow control slots above the throttle plate until at its wide open position, a minimum vacuum pressure is being imported to the variable position spark-advance diaphragm unit.

In the claims, the use of the term atomized or any form thereof shall be used as representative of the atomized state, as it is commonly understood, the near-vapor state, as exists by the minute nature of the liquid particles, and the true vapor state of the fuel which may inherently result from passage of the liquid fuel into an area. of partial vacuum, insuflicient surface tension because of the small nature of the fuel particles to retain the fuel in a minute globule form, and evaporation of the 13 fuel in the region adjacent to the fuel dispenser and in the path to the internal combustion engine.

For ease of description, the principles of the invention have been set forth with but a few illustrated embodiments showing the invention. It is not my intention, however, that the illustrated embodiments nor the terminology employed in describing them be limiting inasmuch as variations in these may be made without departing from the spirit of the invention. Rather, I desire to be restricted only by the scope of the appended claims.

I claim: 1. In a carburetor, the combination comprising: means for adjusting the air intake of said carburetor corresponding to a desired normal engine speed,

primary variable fuel flow control means responsive to said air adjusting means for maintaining a normally constant fuel-to-air ratio under conditions of normal engine operation,

means responsive to said primary variable control means for metering the fuel at said desired normal engine speed, means for dispensing said metered fuel to said intake air about the periphery of said fuel dispensing means, said fuel dispensing means including a foraminous wall and a base portion, said wall and base portion defining a cavity, said cavity being positioned in said carburetor in a manner that liquid fuel from said fuel metering means is dispensed through said foraminous wa-ll, whereby said fuel is atomized and charged into said intake air by a pressure differential across said fuel dispensing means to provide a near homogeneous mixture of fuel and air for presentation to said engine, secondary variable fuel flow control means cooperating with said primary variable fuel flow control means for maintaining one of either an abnormal constant or variable increased fuel-to-air ratio under conditions of abnormal engine operation, means for providing a variable positive pressure in said carburetor cooperating with said primary and said secondary fuel flow control means to reduce said fuel flow in response to a reduced pressure under decelerating engine operation thereby to reduce the fuel-air ratio and to increase said fuel flow in response to an increased pressure under accelerating engine operation to increase said fuel-air ratio,

whereby the fuel-air ratio is thus correlated to the needs of said engine operation under various operating conditions to provide increased fuel economy and to lessen emission of unburned hydrocarbons in the exhaust of said engine.

2. The combination of claim 1 wherein said primary variable fuel flow control means includes a metering valve,

said variable positive pressure means providing a differential positive pressure across said metering valve.

3. The combination of claim 1 wherein said secondary variable fuel flow control means includes:

means for increasing the fuel flow during a condition of engine acceleration, and

means for increasing the fuel-air ratio under conditions of cold engine operation, said fuel-air ratio increasing means including a thermostatic element cooperating with said intake air adjustment means to provide a higher fuel rate of flow while engaging said fuel enrichment means,

said thermostatic element disengaging said fuel flow increasing means under normal engine operation.

4. The combination of claim 1 wherein said primary variable control means for controlling the metering of fuel from a metering orifice of a metering valve to a fuel-air mixing area of said carburetor includes a fuel metering valve and a metering cam pivotably mounted on said intake air adjustment means for operating said fuel metering valve.

14 said secondary variable fuel flow control means controlling the the metering of fuel by varying the position of said metering cam by an engagement with an adjustment means,

said adjustment means being adjustable relative to said intake air adjustment means,

said adjustment means being controlled in its axial location relative to said intake air adjustment means by a member which moves said adjustment means to produce corresponding movement of said metering cam through the pivotable arrangement with said intake air adjustment means, said adjustment means further including an inertial flywheel,

said flywheel being spring biased relative to said intake air adjustment means so that the flywheel is returned to an original starting reference position, said starting reference position being adjustable, said spring being calibrated to produce a precise time delay for providing a temporary fuel enrichment under engine accelerating and choking conditions, and

said base portion and said foraminous wall, form a cup-shaped dispenser whereby metered fuel passing through the foramina in said walls is atomized by the action of intake air in the carburetor passing across the outer surface of said wall so that the atomized fuel is intermixed with the intake air about the periphery of the fuel dispenser, thereby providing a substantially homogeneous mixture of fuel-charged intake air to the internal combustion engine.

5. The combination of claim 4 wherein said primary and secondary control means meter said fuel for presentation to said fuel dispensing means along a single flow path, said secondary control means further including an accelerator pump for increasing fuel flow during engine acceleration, said fuel being atomized by said fuel dispensing means.

6. The combination of claim 1 further comprising:

means for supplying hot gases at a variable pressure to substantially alleviate icing conditions in the carburetor,

an atomization area located in the air flow stream immediately after the liquid fuel dispensing device where the fuel enters the intake air stream and before the throttle air valve,

said means including a hot-gas reference pressure tube mounted in the exhaust system of the engine to produce a flow of exhaust gases at a variable pressure and fiow rate dependent on the velocity of said exhaust gases through the opening of said reference pressure tube mounting plate, said hot-gas reference pressure tube assembly commmunicating with the carburetor by means of a hot-gas carbon trap-flame arrestor assembly having an inlet and outlet tube within a common housing in which these tubes are offset to pass each other slightly so that the hotgas flow from the inlet tube enters the large common area of the carbon trap housing slowing down its velocity and then reversing its direction for travel to the open end of the outlet tube to continue its flow at its original velocity to the atomization area,

said carbon trap housing being separable for periodic cleaning.

7. The combination of claim 1, further comprising:

means for providing a substantially precise control over constant resupplying of fuel to said carburetor and a dependable repeatable reference positive pres sure drop under all driving and climatic conditions across said fuel metering valve,

a combination float and pressure differential diaphragm mechanically linked to an inlet needle valve to allow a controlled supply of'fuel to pass constantly into the carburetor under continuing engine operation in response to movement of said float and diaphragm unit with the liquid level of the fuel supply in the carburetor to maintain a near-constant confinement of the fuel through communicating parts to said fuel metering valve whereby the combination float and diaphragm controls the fuel supply at substantially all attitudes of the carburetor with respect to the horizontal plane so that the said fuel supply is relatively free from interruption. 8. The combination of claim 4 wherein means for providing a positive pressure control to said fuel flow control means is operative so that the positive pressure drop across said fuel flow control means varies in proportion to the need of the engine,

said positive pressure means including a reference pressure tube communicating through suitable connecting passageways to the confined space directly above the fuel level in said carburetor float needle valve controlled fuel supply chamber so that said reference pressure tube reflects the variation of positive pressure wihin said engine at all speeds and conditions of engine operation upon the fuel liquid level surface,

said change of positive pressure being utilized to cause a fuel flow through a fuel metering valve and dispensing means of said carburetor which is a function of the variation in air velocity due to changing engine speed,

said pressure being reflected by the opening in said reference pressure tube to vary said positive pressure to effect a variable positive pressure drop across the metering valve, to aid the metering device in precise repeatable fuel flow control at any and all engine speeds and changes in the air density of intake air with respect to sea level to make a nearly ideal proportional change in said pressure drop across the fuel metering valve and maintain a near constant fuel-air ratio constant in the homogeneous fuel-air mixture.

9. The combination of claim 1 further comprising:

means for producing a variable vacuum pressure control system,

said system including an inverted conical diaphragm operator in a suitable housing,

said operator having an adjustable calibrated spring load and a spring rate which provides vacuum pressure to produce a spark advance position of the distributor breaker points,

said intake air adjustment means communicating with the vacuum side of said inverted conical diaphragm operator, said intake air adjustment means increasing in angular relationship from near closed idling position to its full open throttle position causing the vacuum pressure to vary from a maximum to a minimum and said spark advance position to vary from minimum to maximum. 10. The apparatus combination of claim 1 wherein said intake air adjustment means comprises a throttle plate air valve having a tubular axle,

said primary variable fuel flow control means including a directly acting fuel-metering valve operative in response to positive pressure to produce a resulting force opposed by a precisely calibrated spring such that the position of said direct-acting valve can be repeatably effected at all engine speeds so as to maintain the normally constant fuel-to-air ratio by weight,

said calibrated spring being responsive to movement of an adjustable cam surface operated by a lever mechanically linked for movement in conjunction with an inertial flywheel mechanism associated with said throttle plate axle,

said flywheel being spring-loaded to a fixed bracket on said lever such that the flywheel is always spring returned to the original starting reference position,

said reference position being adjustable by a setting screw on said fixed bracket which engages the radial surface of a dowel pin fixed to said flywheel with said pins axis parallel to the throttle plates axle,

said return spring being of a precise calibrated type to produce a precise time delay with respect to its motion return rate.

11. The apparatus combination of claim 1 wherein foramina of said foraminous wall are of generally poly onal cross section.

12. The apparatus combination of claim 1 wherein the foramina in said foraminated Wall are defined in shape by a truncated pyramid.

13. The apparatus combination of claim 1 wherein the foramina in said foraminous wall comprise a cross-sectional area at a surface of said wall of between approximately 4 10 and approximately 4x 10- square inches.

14. In a positive pressure carburetor having precise fuel metering means with a normally constant fuel-air ratio which is variable under accelerating and choking condi' tions, an apparatus combination comprising:

a fuel metering valve,

a metering cam pivotally mounted on an air valve for operating said fuel metering valve,

fuel dispensing means comprising a cup-shaped fuel dispenser including a base portion and a foraminous wall, the foramina in said wall positioned so that metered fuel may pass therethrough to be atomized by the action of intake air in the carburetor passing across the outer surface of said wall so that the atomized fuel is intermixed with the intake air about the periphery of the fuel dispenser, whereby the intake air effectively shears the liquid fuel into atomized particles at the outside of said foraminous wall and draws the liquid fuel by a venturi action to provide an atomized fuel entrained and intermixed with said intake air.

15. The carburetor combination of claim 14 further comprising means for injecting a suitable additional volume of fuel to the fuel metering valve to establish a new fuel rate of flow in response to a new throttle position for a higher engine speed,

said means including an accelerator pump and a check valve which unseats in fuel path to said metering valve, after accelerator pump has exhausted its added fuel charge through the metering valve.

16. The carburetor of claim 14 further including a combination fioat and pressure differential diaphragm for allowing a controlled supply of fuel to the carburetor under varying conditions of engine operation,

means for maintaining a near-constant confinement of the fuel supply within a sealed chamber,

said sealed chamber including a conical flexible diaphragm in a fuel supply reservoir,

said diaphragm separating the fuel in said chamber of said pressurized carburetor from said fuel metering means so that the fuel supply is accurately controlled in all attitudes of the carburetor with respect to the horizontal plane.

17. The carburetor of claim 14 further comprising means for filtering the fuel supply whereby foreign particles are prevented from entering the fuel dispensing means to block said openings therein by passing fuel flow through a portion of said fuel supply means containing openings smaller than said openings in said fuel dispensing means.

18. The carburetor of claim 14 including means providing a source of positive reference pressure to create a varying positive pressure within said carburetor thereby to admit controlled amounts of fuel from the metering valve under all conditions of engine operations.

19. The carburetor of claim 14 further comprising means for varying positive reference pressure including an exhaust reference pressure tube communicating with the exhaust system of the engine thereby to support maximum fuel economy and performance by an increase or decrease of fuel being metered to the foramina in response to 1 7 variation of pressure in said exhaust reference pressure tube.

20. The carburetor of claim 14 further comprising means for providing hot exhaust gases to said fuel dispensing means to provide anti-icing capabilities under particular atmospheric conditions in which portions of the carburetor would tend to ice.

21. In a carburetor as defined by claim 14 wherein said fuel dispensing means includes nozzle means connected to the casing of the carburetor,

said nozzle means including an extended skirt portion,

said fuel dispenser being positioned relative to said nozzle means in accordance with the position of the metering valve so that fuel may pass through said fuel dispenser to be mixed with the intake air in the throat of the carburetor.

22. The carburetor of claim 14 wherein said precise fuel metering system further includes:

means for controlling the fuel flow rate at engine speeds in the idle range,

means for controlling the fuel fiow rate at engine speeds above the idle range, and

means for shutting off said idle fuel flow rate control means at all engine speeds above said idle range so that the fuel enters the air stream from a path controlled by the means for controlling the fuel flow rate at engine speeds above the idle range.

23. The carburetor as defined in claim 22 wherein said idle flow fuel rate control means includes a positive reference pressure vent valve which is open to the intake air in the idling speed range to vent positive reference pressure.

24. The carburetor as defined in claim 23 further including means for supporting the metering valve in the throat area of the carburetor,

said means including a plurality of legs communicating with a rim located in a recess in said carburetor throat area,

an annular groove in confinement with said recess to provide a porting path for idle flow fuel from the fuel supply reservoir to the idle fiow shut off means.

25. The carburetor as defined in claim 24 comprising:

a cam lobe operative in accordance with the throttle plate air valve position,

a shut-off valve, including a spring-mounted shut-off valve stem and a valve seat,

an idle mixture needle valve for adjusting the idle mixture fuel flow rate so that under idle speed conditions said cam lobe operates said shut-01f valve stem thereby to allow a flow of idling fuel to the idle mixture needle valve.

References Cited UNITED STATES PATENTS 1,097,039 5/ 1914 Miller.

1,312,468 8/1919 Barricklow 261-51 1,970,601 8/ 1934 Funderburk 261-58 1,973,496 9/1934 Moore 123-119 1,974,733 9/ 1934 Armstrong 261-51 2,102,476 12/ 1937 Mennesson.

2,297,550 9/1942 Gistucci 261-691 X 2,310,984 2/1943 Mock et al. 261-69 2,808,245 10/1957 Grover 261-51 3,016,889 1/1962 Sweeney 123-119 3,269,377 8/1966 Fleming 123-119 MARK NEWMAN, Primary Examiner. AL LAWRENCE SMIT H, Examiner. 

1. IN A CARBURETOR, THE COMBINATON COMPRISING: MEANS FOR ADJUSTING THE AIR INTAKE OF SAID CARBURETOR CORRESPONDING TO A DESIRED NORMAL ENGINE SPEED, PRIMARY VARIABLE FUEL FLOW CONTROL MEANS RESPONSIVE TO SAID AIR ADJUSTING MEANS FOR MAINTAINING A NORMALLY CONSTANT FUEL-TO-AIR RATIO UNDER CONDITIONS OF NORMAL ENGINE OPERATION, MEANS RESPONSIVE TO SAID PRIMARY VARIABLE CONTROL MEANS FOR METERING THE FUEL AT SAID DESIRED NORMAL ENGINE SPEED, MEANS FOR DISPENSING SAID METERED FUEL TO SAID INTAKE AIR ABOUT THE PERIPHERY OF SAID FUEL DISPENSING MEANS, SAID FUEL DISPENSING MEANS INCLUDING A FORAMINOUS WALL AND A BASE PORTION, SAID WALL AND BASE PORTION DEFINING A CAVITY, SAID CAVITY BEING POSITIONED IN SAID CARBURETOR IN A MANNER THAT LIQUID FUEL FROM SAID FUEL METERING MEANS IS DISPENSED THROUGH SAID FORAMINOUS WALL, WHEREBY SAID FUEL IS ATOMIZED AND CHARGED INTO SAID INTAKE AIR BY A PRESSURE DIFFERENTIAL ACROSS SAID FUEL DISPENSING MEANS TO PROVIDE A NEAR HOMOGENEOUS MIXTURE OF FUEL AND AIR FOR PRESENTATION TO SAID ENGINE, SECONDARY VARIABLE FUEL FLOW CONTROL MEANS COOPERATING WITH SAID PRIMARY VARIABLE FUEL FLOW CONTROL MEANS FOR MAINTAINING ONE OF EITHER AN ABNORMAL CONSTANT OR VARIABLE INCREASED FUEL-TO-AIR RATIO UNDER CONDITIONS OF ABNORMAL ENGINE OPERATION, MEANS FOR PROVIDING A VARIABLE POSITIVE PRESSURE IN SAID CARBURETOR COOPERATING WITH SAID PRIMARY AND SAID SECONDARY FUEL FLOW CONTROL MEANS TO REDUCE SAID FUEL FLOW IN RESPONSE TO A REDUCED PRESSURE UNDER DECELERATING ENGINE OPERATION THEREBY TO REDUCE THE FUEL-AIR RATIO AND TO INCREASE SAID FUEL FLOW IN RESPONSE TO AN INCREASED PRESSURE UNDER ACCELERATING ENGINE OPERATION TO INCREASE SAID FUEL-AIR RATIO, WHEREBY THE FUEL-AIR RATIO IS THUS CORRELATED TO THE NEEDS OF SAID ENGINE OPERATION UNDER VARIOUS OPERATING CONDITIONS TO PROVIDE INCREASED FUEL ECONOMY AND TO LESSEN EMISSION OF UNBURNED HYDROCARBONS IN THE EXHAUST OF SAID ENGINE.
 14. IN A POSITIVE PRESSURE CARBURETOR HAVING PRECISE FUEL METERING MEANS WITH A NORMALLY CONSTANT FUEL-AIR RATIO WHICH IS VARIABLE UNDER ACCELERATING AND CHOKING CONDITIONS, AN APPARATUS COMBINATION COMPRISING: A FUEL METERING VALVE, A METERING CAM PIVOTALLY MOUNTED ON AN AIR VALVE FOR OPERATING SAID FUEL METERING VALVE. 